While there is a myriad of art covering laser mirrors (e.g., U.S. Pat. Nos. 3,836,236; 3,926,510; and 3,942,880) because of the many peculiar physical property requirements of such mirrors in this environment, a variety of materials, designs and forming methods have been employed in attempts to optimize the particular properties necessary for a composite used in this particular environment. For example, a laser mirror in this environment must not only have the requisite reflective properties but should be a relatively simple structure to permit rapid fabrication, both for time and cost purposes. Such mirrors should also desirably have low density for ease of use in the types of apparatus where they will be used. Furthermore, such mirrors ideally should have high elastic stiffness and high strength along with high fracture toughness. And stability is of the utmost importance both from the point of view of the fine resolution-type work environment the mirrors will be used in, and the inaccessibility of the apparatus which these mirrors would be used in, for example, outer space applications. These stability properties include low thermal expansion, high thermal conductivity, and environmental stability. Environmental stability includes such things as dimensional stability and mirror integrity regardless of moisture conditions, vacuum conditions, or ultraviolet light exposure, and mirror integrity and dimensional stability at both high and low temperatures. Currently, laser mirrors are basically either highly polished metal blocks formed by highly labor intensive polishing processes (high energy laser application), or graphite reinforced resin matrix composites or low expansion glasses (low energy laser application). However, because such currently used composites and glasses fall off in one or more of the above-cited property areas, it is generally necessary to include a myriad of complicated designs and manufacturing procedures to compensate for property defects in the particular areas under consideration. Note for example, the complicated coolant designs in the above-cited references. Furthermore, the popular use of resins in conventional composites of the above type inherently suffer from dimensional changes due to absorption or desorption of moisture, evolution of organic constituents due to prolonged exposure to high vacuum, breakdown due to prolonged exposure to ultraviolet radiation, low thermal conductivity, high coefficients of thermal expansion, and rapid decrease in integrity when used above 300.degree. C.